[RESOLVED] winsock error handler

[drivenbywhat]

I have the following code. It's a simple client/server chat. Can someone please tell me what errors to look for when using winsock and how to handle/avoid them. I know if I press the button to LISTEN or CONNECT when it's doing that stuff already, the program errors out.

Option Explicit
 
Private Sub cmdconnect_Click()
 
Winsock.RemoteHost = txtIp.Text  ' this is the Ip of the server 127.0.0.1 loops back to your own computer
Winsock.RemotePort = 15151  ' this is the port it must be the same as the server
Winsock.Connect  ' connect!
 
End Sub
 
Private Sub cmdListen_Click()
 
Winsock.LocalPort = 15151 'open the port on the local machine try to use ports between 3000 and 50000
Winsock.Listen ' start listening, simple!
 
End Sub
 
Private Sub Winsock_ConnectionRequest(ByVal requestID As Long)
 
Winsock.Close 'this resets our socket ready to accept the incoming connection
Winsock.Accept requestID 'accept the connection!
 
End Sub
 
Private Sub winsock_DataArrival(ByVal bytesTotal As Long)
 
Dim incommingData As String 'this stores the data we receive
 
Winsock.GetData incommingData ' this stores the data in the variable we set above
 
' now we will display it in the textbox
 
txtChat.Text = txtChat.Text & vbCrLf & incommingData
 
End Sub
 
Private Sub cmdSend_click()
 
Winsock.SendData txtMessage.Text ' sends the data in the textbox
txtChat.Text = txtChat.Text & vbCrLf & txtMessage.Text
 
End Sub

[DigiRev]

You can't use Listen, Connect, SendData, or set some of the other properties (RemoteHost, RemotePort, LocalPort) if you are already connected. This is why it's always a good idea to use Winsock.Close before any of those methods.

Some things to know if you don't already:

If there is an error connecting, the Winsock_Error() event will fire. Use the Number and Description arguments to see more about the error.

If the other end closes the connection, the Winsock_Close() event will fire.

You can also check the Winsock.State property before trying to send data or whatever. Here is a list of the Winsock states.

sckClosed = 0
sckOpen = 1
sckListening = 2
sckConnectionPending = 3
sckResolvingHost = 4
sckHostResolved = 5
sckConnecting = 6
sckConnected = 7
sckClosing = 8
sckError = 9

[drivenbywhat]

That's good stuff to know DigiRev. One question about your response that I have is where you say:

"You can't use Listen, Connect, SendData, or set some of the other properties (RemoteHost, RemotePort, LocalPort) if you are already connected."

I learned the hard way about LISTEN & CONNECT. You can't use those if you are already connected. I got that. However, you also say SendData can't be used if you're already connected. Shouldn't one be able to send data now that they are connected? Why should one close winsock for this? Did you type that by mistake or am I missing something? Because if SendData should be closed before sending, then wouldn't the same be true about GetData? I'm confused now.

[DigiRev]

That's good stuff to know DigiRev. One question about your response that I have is where you say:

"You can't use Listen, Connect, SendData, or set some of the other properties (RemoteHost, RemotePort, LocalPort) if you are already connected."

I learned the hard way about LISTEN & CONNECT. You can't use those if you are already connected. I got that. However, you also say SendData can't be used if you're already connected. Shouldn't one be able to send data now that they are connected? Why should one close winsock for this? Did you type that by mistake or am I missing something? Because if SendData should be closed before sending, then wouldn't the same be true about GetData? I'm confused now.

Sorry to confuse you, not sure why I typed that. SendData can ONLY be called when connected or you will get an error.

Unless Winsock's Protocol property is set to UDP. UDP is a "connectionless" protocol so you can send data without connecting.

[drivenbywhat]

Ok, cool. I'm un-confused again.

PS
Seems every body is on vacation or something. Could you take a look at my other post when you have a chance. Thanks.

http://www.vbforums.com/showthread.p...79#post2934779